Treating process for hydrocarbon oils



Patented June 28, 1932 UNITED STATES,

PATENT OFFICE BOY CROSS, OF KANSAS CITY, MISSOURI, ABBIGNOB T GROSSDEVELOPMENT CORPORA- 'l'ION, OF WILMINGTON,'DELAWABE, A OOBPOBATION OFDELAWARE TBEATIH G PROCESS FOR HYDBOQABBON OILS No Drawing.

This invention relates to improvements in the process of refiningpetroleum oils such as gasoline, medicinal oil, lubricating oils,industrial naphtha, machine oils and the like.

It more particularly relates to the purification of hydrocarbon oils oroils consisting largely of h drocarbons. Among its purposes are theollowing:

1. For removal of sulphur.

m 2. For removal of color and to produce water white products.

3. For removal of obnoxious odors.

4. For stabilizing the oil as to color and odor.

In the practice of this invention metals or the hydrides of metals ofthe alkali and alkali earth group are used. These metals include, intheir order of usefulness and availabilitymetallic sodium, metalliccalcium, metallic potassium, metallic magnesium, metallic strontium,metallic barium, metallic lithium.

, Some of the important properties in conve sidering this invention maybe tabulated as an follows:

Combining Melting Specific Metal equivalent point gravity 0. Sodium 2397.6 0.971 0alcium.. 20 805 1.54 Potassium a9. 1 ea 5 a. an

M esium 12 650 1. 70 B um 6B 850 3.78

It has been found that all of these metals and their hydrides react withpetroleum oil to efiect a removal of sulphur, a removal of color, apolymerization of unsaturated compounds and a stabilization of thehydrocarbons to a more or less variable'degree. As to sulphur removal,the alkali metals, such as though magnesium and calcium are more ef-Application illed June 28,

potassium and sodium, are very active,

1920. Serial a... 119,111.

als. The method of ap lication will, of course vary in each case. n someinstances it is desirable to use a combination of the metals. This isparticularly well illustrated in the use of mixtures of metallic sodiumand metallic potassium. Although the melting pomt of metallic sodium isapproximately 97 C. and of metallic potassium approx1- mately 63 (3., amixture of two gram molecules of potassium with 1 gram molecule ofsodium has a melting point of 10 0. below zero, All intermediatetemperatures can be obtained by using the appropriate percentages. Inthe same way mixtures of alkali metals and alkali earth metals can beused to give products of low melting point. Productsor appropriatemeltin point can be made to correspond with tle temperatures at which itis desired to treat the hydrocarbon. For exam le, if it is desired totreat mm having a melting point of 0 C. may be used and the gasoline maybe bubbled directly through the metal mixture, or the metal mixture maybemade to flow in opposite direction and in contact with the flow of thehydrocarbons. The sulphides or precipitates formed in the metal can thenbe continuously removed from the system and purified to return only thepure metal.

There is a great varietyof ways of appl ing these metals or metalhydrides for t e removal of sulphur, color and to otherwise purifyhydrocarbon oils. Some of the important methods may be classified asfollows:

1. The metal is contacted either hot or cold and either with the 'hotliquid or the hot vapor of the oil to be treated. A suitable method ofccntactin is to first mix the metal thorou hly wit a heated bleachingclay or other fiist'ributing material and then use this material fortreating the vapors or the liquid oil. This material may be a pliedeither by passing the vapors throug the metal treated clay in a tower orby mixin the clay with the liquid oil and filtering o the metal mixedcla One suitable method in the treating of 1 light gasohne, a mixture ofpotassium so cracked gasoline is to contact the asoline fairly quicklywith sulphuric acid 0 a gravity usually of from 60 to B6. The acid is.then very quickly removed, preferably by the use of a centrifuge. Thegasoline is then continuously mixed with the metal coated clay which isquickl pumped through a filter press such as a weetland filter.- Theproduct is lar ely desulphurized, has a fairly good odor an has a waterwhite color. As a general rule, however, the higher the temperature oftreatment the more complete is the sulphur removal, although it 18 notnecessar to use the higher temperatures to get a go bleaching efi'ect.For complete sulphur removal it is necessary to have sufficient metal toreact with all of the sul hur. It is,'of course, always important to e1minate insofar as possible any water or steam from the oil beforetreating. This method of treatment applies to other oils, such aslubricating oils, painters naphtha and the like where ood color and lowsulphur content are deslrable.

2. The treatment may also be applied by pumping the liquid or vapordirectly over the metal in granular form. Th1s metal may be granulatedby meltin and the unused metal may be recovered y remeltmg and removingthe impurities, the treatment, however, being efiected on the surface ofthe metal in solid condition.

3. In many instances treatment may be effected by bubbling the liquidthrough the molten metal or mixtures of metals. This method of treatmentis convenient as it can be carried out in completely enclosed containers, and also will allow the circulation of the metal as well as thehydrocarbon oil and in counterflow to each other. This treatment may beeffected at almost any desired temperature as alloys or mixtures can bemade having melting points from 10 C. below zero In the treatment ofhydrocarbon oils with alkali and alkali earth metals it has beenpossible to remove a varying percentage of the sulphur. The sulphurexists in the oil in a number of different combinations, including suchsubstances as-- Mercaptans, thio-alcohols or alkyl hydrosul hides=RHSlkyl disulphides=R S Sulphine or sulphonium compounds= RSSCI Sulpnones=RSO Sulphonic acids=RHSO Thio-sulphonic acids=RHS O Sulphinic acids=RHSO2The amount of sulphur removed has varied in difi'erent types of oilsfrom 10% to 95%. This varies also with the method of treatment and theparticular metal used. Potassium and sodium metals and potassium andsodium hydrides are most efiective at lower tempercium 15 veryefl'ecive. Magnesium 1s apparently least effective of all, although insome instances it is more efl'ective for color removal than the othermetals.

It is not perfectly clear just how these metals effect so completeremoval of the sulphur without destroying the molecule, but the lowpercentage of loss, in most cases being much less than 3%, indicatesthat the sulphur is extracted from the molecule and the hydrocarbonportion of the molecule either forms a new molecule or undergoes arearrangement of the hydrogen atoms. Probable reactions may be shown bythe following symbolic reactions, assuming M to represent the metal, Hto represent the hydrogen and R to represent the hydrocarbon radicalinvolved. The reacatures, although at higher temperatures caltion of amercaptan would be approximately as follows RSH M=RH MS or, as aspecific instance using ethyl mercaptan or sulphhydride,

C2H5SH Ca C H In the case of an alkyl sulphide reaction might be asfollows:

RS+MH=MS+RH or, in the case ofan alkyl disulphide:

R S+M=RR+MS cracked gasoline in its raw state frequently hasfrom 0.2% to1% of sulphur. By the ordinary methods of refining with sulphuric ac1dall of the molecule combined with the sulphur is removed, thus entailinga loss ofpften as much as 40% of the gasoline when it is desired toproduce a product having less than one-tenth of one per cent of sulphur.With this method of treatment, however, the loss 1n extreme instanceswould rarely exceed 5 California gasoline is particularly hard to treatand by this method it has been found possible to remove in mostinstances from 50% to 90% of the sulphur in the gasoline without anysubstantial losses of volume.

I claim as my invention:

1. A method of treating petroleum, which consists in continuouslypassing the petroleum in intimate contact with a metal of the alkalineearth group in a liquid state, the said said oil, and removing thepurifyin mamas metal caused to flow in an opposed direction to thedirection of flow of the petroleum to efiect a chemical combination withsaid metal, continuously removinv and purifying the metal, andcontinuously removing and cooling the petroleum.

2. A method of treating petroleum, which consists in continuouslypassing the petroleum vapors in intimate contact with a liquid alkalineearth metal, the liquid metal passing in an opposed direction to thedirection of flow of the petroleum to efi'ect a chemical combinationwith said metal, continuously removing and purifying the metal, andcontinuously removing and cooling the petroleum.

3. A method of treating petroleum oil which consists in continuouslypassing the petroleum in intimate contact with metallic calcium, thecalcium being heated above its meltin point, the calcium passed in anopposed direction to that of the flow of the petroleum oil to efiect achemical combination between the calcium and the impurities in metal andcontinuously removing and cooling the treated oil.

4. A method of treating petroleum oil which consists in continuouslypassing the petroleum in intimate contact with metallic calcium, thecalcium being heated above its meltin point, the calcium passed in anopposed ireetion to that of the flow of the petroleum oil to effect achemical combination between the calcium and the impurities in said oil,continuously removing the purifying metal and continuously removing thepurified oil from the system.

5. The method of desulphurizing and de colorizing hydrocarbon oil,including the step of contacting said oil with an alkaline earth metalto effect a chemical combination between said alkaline earth metal andthe sulphur compounds to be eliminated.

6. The method of desulphurizing and dccolorizing hydrocarbon oil,includin the steps of contacting said oil with an alkaline earth metalto effect a chemical combination between said alkaline earth metal andthe sulphur compounds to be eliminated, continuously removing thechemical compounds thus formed.

7. The method of dcsulphurizing and dccolorizime hydrocarbon oil,including the steps of contacting said oil with an alkaline icalcombination between said alkaline earth metal and the sulphur compoundsto be eliminated.

9. The method of desulphurizing and decolorizing hydrocarbon oil,including the step of contacting said oil with an alkaline earth metal,incorporated with an argillaceous material, to effect a chemicalcombination between said alkaline earth metal and the sulphur compoundsto be eliminated.

10. The method of desulphurizing and decolorizing hydrocarbon oil,includin the steps of contacting said oil with an al aline earth metal,incorporated with an argillaceous material, to effect a chemicalcombination between said alkaline earth metal and the sulphur compoundstobe eliminated, and continuously removing the compounds thus formed.

11. The method of desulphurizing and decolorizing hydrocarbon oil,including the steps of contacting said oil with an alkaline earth metal,incorporated with an argillaceous material, to effect a chemicalcombination between said alkaline earth metal'and the sulphur compoundsto be eliminated, continuously removing the compounds thus formed, andsubsequently removing said metal from said compound.

12. The method of desulphurizing and decolorizing hydrocarbon oil whichincludes the steps of continuously passing the oil in a vapor phase, incontact with an alkaline earth metal in liquid form to effect a chemicalcombination between said alkaline earth metal and the impurities to beeliminated from said hydrocarbon, resulting in a precipitate of saidcombination, and continuously removing said precipitate. V

13. A process as in claim 12 in which the hydrocarbon flows in adirection counter to the alkaline earth metal in liquid form.

14. A process as in claim 5 in which the alkaline earth metal iscalcium.

15. A process as in claim 5 in which the alkaline earth metal is barium.

16. A process as in claim 5 in which the alkaline earth metal ismagnesium.

17. A continuous method of purifying petroleum hydrocarbons includingthe steps of vaporizing the hydrocarbons and bringing the evolved vaporsinto intimate contact with an alkaline earth metal in a liquid state,continuouslycirculating said liquefied alka line earth metal in counterflow relation with said hydrocarbon vapor, to form polymers by chemicalaction, diverting saturated olymers and reactionproducts and supp yingadditional unused treating metal.

ROY CROSS.

